All VC get stomped.
All senior captains and Zaraki win. At that point of the story Byakuya was extremely reliant on his Bankai so he would probably lose. He struggled against Zomari with his Shikai and on his fight against Yami he was constantly in Bankai.
Zaraki was fighting against Yami on his rage mode and was pressing him very hard while being significantly injured.
Senior captains are all beasts. Unohana for that matter would probably demolish the entirety of the Espada solo.